Description. — Shell conical, elongate, fragile, with convex whorls and a deep suture. The protoconch measures 180 µm and has almost 1.25 whorls. The nucleus measures only 30 µm and is more deeply buried in the whorl that surrounds it. The upper part of the whorls is almost smooth with opistocyrt curved growth lines that are more visible on a subsutural band, and very tiny, impressed spiral lines. The lower part of the whorls has only a few (6-7) very wide furrows with narrow interspaces that are intersected and offset by a few slightly irregular axial slightly prosocyrt ribs without forming rectangular pits. Operculum with a subcentral nucleus and prominent peripheral curved wrinkles. Dimensions: the holotype measures 1.6 mm
Distribution. — Only known from the type locality.
Etymology. — The specific name is composed of the Latin words latus-a-um, "wide" and sulcatus/a "furrowed" which means that it has broad furrows.
Remarks. — This species can be distinguished from other Pacific species, mainly by its very wide spiral furrows which have narrower intervals, like cordlets. Furthermore the protoconch has more than one whorl and its nucleus is placed further inward.
The shell described by Fukuda, Nakamura & Yamashita (1998) as Murchisonella sp. could be a juvenile of this species.
Murchisonella declivita has a wider protoconch and its nucleus is not placed so deep into the whorl. The protoconch has only one spiral whorl, whereas the initial part of the teleoconch has impressed pits that are also present in the furrows of the entire shell. The upper part of the whorls is narrower and the separation forms a more marked step.
Murchisonella arabica has the axial sculpture more dominant in both parts of the whorls.
Murchisonella modesta spec. nov. has shells that are larger, smoother and almost without the important separation of the two parts of the whorls.
Murchisonella occidentalis has larger shells, the upper part of the whorls is narrower, whilst in the lower part of the whorls the furrows are narrower and more numerous, and for the same shell size it is wider with less whorls.